Means for checking the operation of a track instrument



March 18, 1958 R. R. KEMMERER MEANS FOR CHECKING THE OPERATION OF ATRACK INSTRUMENT Filed Dec. 21, 1953 w --.wi------i-----:5-------ili----Q a b M WK 5 M m u 0 WI 0 W a b a C\ WW I INVENTORL x Havb 12, IfemmererUnited States Patent Qfiice Patented Mar. 18, 1%55'5 MEANS FOR CHECKINGTHE OPERATION OF A TRACK INSTRUMENT Ralph R. Kemmerer, Swissvale, Pa.,assignor to Westinghouse Air Brake Company, Wilmerding, Pa, 21corporation of Pennsylvania Application December 21, 1953, Serial No.399,201

13 Claims. (Cl. 246-160) My invention relates to means for checking theoperation ofa track instrument.

Track instruments are often used along the wayside of a stretch ofrailway track in order to detect the presence of trains and vehiclesmoving through the stretch. Such track instruments may take many forms,such as microphones, photoelectric units or treadle actuated railcontactors such as that shown and described in Letters Patent of theUnited States No. 2,588,798, issued March 11, 1952, to Herbert L. Boneand Kenneth J. J. Mc- Gowan, for Buffer Means. Track instruments areusually employed in place of track circuits where it is inconvenient oruneconomical to utilize track circuits for the particular application.Ordinarily, in track instruments, 2. contact is operated when a traincomes into engagement with or in close proximity to the track instrumentand when the train moves out of engagement with or out of closeproximity to the track instrument, the instrument contact will berestored to its normal condition. Therefore, if it is desired to providea continuous indication of the presence of a train in a stretch of trackeven though the train may not be close to nor in engagement with thetrack instrument at the particular time, some additional apparatus isnecessary.

One example of an application in which a track instrument may replace atrack circuit is in a switch locking arrangement. Ordinarily, when ahand-throw switch is employed, a switch lock is employed for preventingthe switch from being thrown to its reverse position while a train isapproaching the switch. However, if it is desired to move a trainapproaching the switch along the main line into a siding, therebynecessitating a reversal of the switch, there must be means provided forunlocking the switch. In the past this has been accomplished byutilizing a short track circuit immediately in approach to the switch,which when occupied, would place the switch in a condition to becomeunlocked, thereby conditioning the switch for a reversal of position.Such a function can be performed by employing a track instrument.

One object of my invention is to provide means for checking theoperation of a track instrument.

' Another object of my invention is to provide means for checking theoperation of a track instrument so that a continuous indication of thepresence of a train or vehicle ina particular portion of .a stretch ofrailway track will result.

It is a further object of my invention to provide, in

means for checking the operation of a track instrument,

rection when the train has moved to within a. predetermined distancefrom the switch. The stretch of track in which the switch is located isprovided with the usual track circuit, and associated with theinstrument are two control relays. The first control relay is providedwith an energizing circuit which becomes closed only when the tracksection is occupied, the track instrument occupes its normal positionand the second control relay is deenergized, and with a stick circuitwhich becomes closed as soon as the first control relay becomesenergized. The second control relay is provided with a pickup circuitwhich becomes closed only when the track section is occupied and thetrack instrument is actuated by a train, and a stick circuit whichbecomes closed when the second relay picks up provided the first relayis then energized. The lock can only be energized when both relays arepicked up. It follows, therefore, if the track instrument is notoperating properly so that it is blocked in its actuated condition, orits contacts are bridging, when a train approaching the switch entersthe section, the second relay will become energized to prevent the firstrelay from becoming energized. Accordingly, the switch lock cannot beenergized to unlock the switch direction and the track instrument isfunctioning iminstrument but may be used whenever the operation of anytype of track instrument must be checked.

The single accompanying drawing is a diagrammatic view of apparatus forthe control of a railway switch employing a track instrument foreffecting an unlock of the switch and means for checking the operationof that track instrument embodying my invention.

Referring now to the drawing, a stretch of railway track made up of thetrack rails 1 and 2 is provided with an insulated track section LT bythe inclusion of insulated joints 3 in the rails. A switch W connectsthe section with a siding S made up of rails 6 and 7. A portion of thesiding S sutficiently long to extend beyond the fouling point of theswitch is preferably insulated from the remainder of the siding byinsulated joints 3, and this insulated portion of the siding isconnected with the rails in section LT by a jumper 4 and the frogarrangement at the switch.

.LT a short distance from the switch so that whenever a train approachesthe switch in a facing point direction, that is, from the left as viewedin the drawing, the track instrument will be actuated by the train. Thedistance between the instrument and the switch may vary but it ispreferably approximately fifty feet. The track instrument WLZ, as hereshown, is provided with a normally closed contact a which becomes open,and a normally open contact b which becomes closed whenever theinstrument is actuated by a train or vehicle.

The track instrument WLZ and the track relay LTR controla first controlor stick relay WLZNPR and a second control or stick relay WLZSPR. RelaysWLZNPR occupied, track relay L normal position.

tissues -and WLZ SPRin connection a manually operated contact, hereshown as a push button contact PB, control a switch lock. WL operativelyconnected with a switch lever K for manually operating the switch W.

The switch lock WL may be ofany of the well-known types and isillustratedconventionally in the drawing. For purposes of my presentinvention, it is snificient to point out that when the switch lock WL isdeenergized and switch W is in its normal position, pawl P will fall:into a notch in a lever quadrant' Qfforming part of the switch lock WLto prevent switchlever K from moving 7 the switch W out of its normalposition. However, when dition of, switch lock WL. As shown, push buttoncontact PB is open. ln actual priactice, thepush button contact PB wouldpreferably be. a contact associated with a normally lockeddoor on:th eswitch lock WL; 'When such an arrangement is used,,a trainman desiringvto operate switch W will unlock and open the. door. thereby closin plshbutton cameras, .In order to restore the door operated contact toitsnormally. open positifn, the

switch W will be free to be restoredqto its normal position by operatinglever K to its normal position, and the trainrnan will do this as soonas the rear end of the train clears the switch W, whereupon pawl P willagain drop into the notch of levernquadrant Q to relock the switch W inits normal position.

It will be obvious thatif a train, isL CQHPYing Section LT when thetrainmanattemptsto. reverse the switch W, the reversal will not beaccomplished since track, relay LTR will be released, thereby ,.openigjt eiprevic ly traced energizing circuit for switchlock causing theswitch W to remain locked. It will be seen, therefore, that .a train.cannot move out of siding S onto the main stretch of track while sectionLT is occupied.

I will now assume thata train enters section LT from the left and thatit is desired to move the train out of the main stretch oftrack ,Q Isiding at switch-W. Upon the train entering section ,LT, relay .LIRjvillrelease and willthereby close an energizing. circuit for relay WLZNPRpassing from positive terminal B of battery LB, over back contact u ofrelay LTR, front trainrnan must. close an'dfll ockthe door.' Such anarrangement will prevent 'unauthorizedpersons from reversingthe switchW. Actually, the inclusion iof push button contact PBis notjnecessary tothe operation of my trackntinstrurnent,checking means but it .isdesirable in the. embodimentshown for reducing drain on batteti'yLB bymaking switch lock WL normally, deenergized,.vand it is, necessary froma safety, standpoint in such an embodimentfto kepiswitch W. locked atall times except when "authorized personnel .desire .to .nnlock Itheswitch W.

The,energy.jfor operating the. relays WLZNPR and WLZSPR and switch lock.WL, gas here shown. is supplied by a battery LB havi ng'a positiveterminal B and a negativeterminalN, a

The apparatus is shown in itsnorrnal condition with the stretch of trackunoccupied and switch W in its normal position, therebyiperrnittingtrafiic to move along the stretch but not into or out of siding 'S Withthe stretch un- R is e'nergized and no energy is be ing supplied torelays WLZSBR and WLZNPR. Therebutton contact PB is open so that noenergy is supplied to switch lockWL arid, aeeq d 7 V n of lever quadrantQ, thereby locking the switch W in its I will'now assumelth at atrainIorvehIcle moving along thesiding S from right toleftdeirestoienter the main trackn these, s fiifi h rzvt hetra n. w top inapproach to the fouling;poinL-ofthe switch and thetrain- .come energizedandnpawl; .P will-belifted outlof the .notch-in lever quadrant Q tothereby unlock switch W andpermit the trainman to reverse the switch.'As soon as the-trainma-n has reversed switch WVQthe-train may move outonto the main stretch oftrack. T rack relay LTR' will release as soon asthe traiii 'passe's the fouling I point andw the releasing' of r elayLTR will -open the energizing circuit for switch lock -'WL. P ushfbuttoncontact PBmay now be allowed to return to itsinorm'ally f'open mgly,-.paw l P is in the notch position. With-switcli' deen'er'gi'zedfpawl 'Pwill dfopontgthe periphe W e fi sincethe switch is i ,itszreverseposition pawl} eannot dr p into the notch to lock switch W. Accordingly,

contact a of track instrument, .WLZ, back contact a "of relay WLZSRR andthe Winding ,of relay WLZNPR to negative terminalN ofnbattery LB.,Accordingly, relay WLZNPR which is a ,slow pickup relay will pick upfafter a short interval of. time, and will establish a stick circuit:including back contact a of relay. LTR.and front contact a of relay WLZNPR. Thissstick circuit will cause relay WLZNPR to remainenergized solong as. section LT "continues totbe oc cupied by the train. Whenthetrain 'aetuates track instrument. VLZ, it will open its front contact aand .close its back contact b. With normally open contact b now closed,a circjuitwillrbe established for energizirig. relay. WLZSPR passingfrom positive terminal B ,oibatteryLB, over back {contact a of relayLTR,, b-ack contactb ofQtrack instrument WLZ and the winding of relayWLZS PR} to .negativeterminal N of battery.1L B., .WithEeIay WLZSPRpicked up, a stick circuit passing from positive terminal B of batteryLB, over back contacts ofi r elay; LTR, front contact b ofrelay,WLZSPR,;.front contact I) of relay WLZNPR and the winding of(relay WLZSPRto negative terminal N of battery LB will beeomeestablished, and relay WLZSPR w ill there'fore' remain energized so'long as the train oceupies gsection LTR; It will be seen that once thestru rne nt WLZ has lqeen initially actuated, there I w ec ri iti Q f eapparatus when the trackgins trurrien contacts; arerestored to theirnormal .condition aften the; first, set lot wheels rnove s .out of, en'-gagement with track instrument WLZ and then are re- .cur rently operatedas other :wheels actuate track instru- J L 1 199 th st ck c r its suppgy to relays WLZ NPR and WLZSPR are notcontrolledby the track instrumentcontacts. It will also be obvious' that track instrument WLZ;may be made.sufiiciently slow acting to remain in its actuated condition ratherthan; rnoving between its actuated and normal conditions eachtimethewheels of a train move into and out of engagement with thetrackinstrument WLZ. This wi1l, however,: have .no effect upon the operationof the apparatuses already described. .7 a

.When. the train reaches switch W, 'a vtrainman will close the pushbutton contact. PB. Accordingly; a second energ izin'g'circuit for.switch lock WL will be established passing from positive terminal B ofbattery'LB, over push button contact PB, front contact a of relayWLZNPR, front-contact c of relay WL ZSPR' and'the winding ofswitch lockto negative ,termi nal bl of V f notch in" lever guadranfQand thewimamaibe willrestore the switch W to its 'normalp'os'ition'in whichlever quadrant Q will be moved to theposition in which pawl P is alignedwith the notch in the quadrant Q, and as a result the pawl P will dropinto the notch as soon as the trainman opens the push button contact PB.This will normally be accomplished automatically by restoring the dooron the switch lock WL to is normally closed condition. When the trainvacates section LT, relay LTR will pick up, thereby deenergizing relaysWLZNPR and WLZSPR and restoring the arrangement to its normal condition.

A desirable feature of my invention is achieved by the requirement thatrelays WLZNPR and WLZSPR must operate in proper sequence in order tounlock switch W. Because of this requirement false operation of theapparatus will be prevented in the event that track instrument WLZbecomes blocked in its operated position with normally open contact bclosed and normally closed contact a open. If this is the case, when atrain enters section LT and relay LTR releases to thereby close thepreviously traced energizing circuit for relay WLZSPR, relay WLZSPR willpick up and prevent the subsequent closing of the energizing circuit forrelay WLZNPR including back contact a of relay WLZSPR. With theenergizing circuit for relay WLZNPR open, it will be obvious that thesecond traced energizing circuit for switch lock WL cannot be closedand, accordingly, switch W cannot be unlocked. This will give a positiveindication to the trainman who is attempting to throw the switch thatthere is something faulty in the apparatus and therefore will assureprompt repair.

In the event that track instrument WLZ became blocked in a position inwhich its contacts were bridging, that is, both contacts a and b wereclosed, upon a train entering section LT, relay LTR would release andthereby energize both relays WLZSPR and WLZNPR over their previouslytraced energizing circuits. However, with relay WLZNPR provided with aslow pickup characteristic, relay WLZSPR will pick up prior to relayWLZNPR and thereby open the energizing circuit for relay WLZNPR at backcontact a of relay WLZSPR. Accordingly, relay WLZNPR will not becomeenergized and, therefore, switch lock WL will not become unlocked. It istherefore assured by my novel arrangement that switch W can only beunlocked when the apparatus is operating in a proper manner.

Although I have herein shown and described only one form of my novelmeans for checking the operation of a track instrument, it will beunderstood that various changes and modifications may be made thereinwithin the scope of the appended claims without departing from thespirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination with a stretch of railway track provided with a tracksection, a track instrument in said track section, first and secondrelays; trafiic responsive means operatively connected to said tracksection and actuated to a first position when said section is occupiedand to a second position when said section is unoccupied, circuit meansclosed when said traflic responsive means is in its first position, saidsecond relay is deenergized and said track instrument occupies itsnormal position for energizing said first relay; circuit means formaintaining said first relay energized as long as said section remainsoccupied, circuit means for energizing said second relay when saidsection is occupied and said track instrument is actuated, circuit meansfor maintaining said second relay energized as long as said sectionremains occupied, and control means controlled by said first and secondrelays.

2. In combination with a stretch of railway track provided with a tracksection, a track instrument in said section, a first relay provided witha slow pickup characteristic, a second relay; circuit means closed by atrain occupying said track section, said second relay in its deenergizedcondition and said track instrument in its normal position forenergizing said first relay; circuit means for maintaining said firstrelay-energized as long as said section remains occupied, circuit meansfor energizing said second relay when said section is occupied and saidtrack instrument is actuated, circuit means for maintaining said secondrelay energized as long as said section remains occupied, and controlmeans controlled by said first and second relays.

3. In combination with a stretch of track provided with a track section,said track section being provided with a track circuit including a trackrelay, a track instrument in said section, a first relay provided with aslow pickup characteristic, a second relay; means elfective when saidtrack relay is deenergized, saidtrack instrument occupies its normalposition and said second relay is deenergized for energizing said firstrelay; a stick circuit for said first relay closed when said track relayis deenergized, means effective when said track relay is deenergized andsaid track instrument is actuated for energizing said second relay, astick circuit for said second relay closed when said track relay isdeenergized, a control device, a first means efiective only when saidtrack relay is energized for energizing said control device, and asecond means effective only when said first and second relays areenergized for energizing said control device.

4. In combination with a stretch of railway track provided with a tracksection, a switch and a track instrument in said section, said switchand track instrument being so located in said section that a trainapproaching said switch in a facing point direction will actuate saidtrack instrument before reaching the switch, a first slow pickup relay,a second relay; circuit means closed by a train occupying said section,said track instrument in its normal position and said second relay inits deenergized condition for energizing said first relay; stick circuitmeans effective as long as said section remains occupied for maintainingsaid first relay energized, circuit means for energizing said secondrelay when said section is occupied and said track instrument isactuated, circuit means for maintaining said second relay energized aslong as said section remains occupied, a switch lock for preventing saidswitch from being reversed when said switch lock is deenergized, circuitmeans for energizing said switch lock when said section is unoccupied,and circuit means for energizing said switch lock when said first andsecond relays are energized.

5. In combination with a stretch of track provided with a track section,a trafiic responsive element having a control contact associated withsaid track section, a track instrument in said section, a first relayprovided with a slow pickup characteristic, a second relay; meanscontrolled by said control contact, said track instrument and saidsecond relay for energizing said first relay, a stick circuit for saidfirst relay controlled by said control contact, means controlled by saidcontrol contact and said track instrument for energizing said secondrelay, a stick circuit for said second relay controlled by said controlcontact and said first relay, and control means controlled by said firstand second relays.

6. In combination with a stretch of track provided with a track section,said track section being provided with a track circuit including a trackrelay, a track instrument located in said section, a first relayprovided with a slow pickup characteristic, a second relay; meanscontrolled by said track relay, said track instrument and said secondrelay for energizing said first relay; a stick circuit for said firstrelay controlled by said track relay; means controlled by said trackrelay and said track instrument for energizing said second relay, astick circuit for said second relay controlled by said track relay andsaid first relay, and control means controlled by said first and secondrelays.

7. In combination with a stretch of track provided con- 7 .P YJ @W t Iwl k v eha a t i a m le'yi w t in d n fa a kfi mct of saidtraclc relay,"saidfir'st' contact and a'baclrcontact oflsaid' secondlrel'ay' for"er1erg ing d first relay; a hunt for saidfifst frelay riding a backcontact of saidtrack rlay; nieans including a back coiitact of saidtrack relay and said second contact for energizing said 'sicond rlay,stick 't tor d" 'secjond' relay incliidin a backkfont'act oflsard traick relay 'nd a front contact or said first relay fgnd control 'nieanls''inclrfrding affront conta c l'of-i ea chbf said first ands 'econdireys.

9. "Irigoinbifiation; a 'str e tcf'zhof ilway traclg groyided aim a"track section; said trad section having a's'sbcia'ted therewith: atrackicircliit inc'ln g a'tracli relay; atr 'ac'k rist'rnrfient haying adrs t normally; closed contact and a second aqrmauy c gpen conta'ct, a.switch; said trackinstriirnen'taiid 's a id switch being] ted in said,track'fsection in such riiar' nerithat whenej er afltrairi orlvehiclapproaches said switch throrigh said section for a facing 'point'inove,saidtrack'insti uinent will be actuated'prior to'thetr'ainraching' saidjswitc a first. relaybr'ovided with a slow p'ickii pcliaracteri'sticQ a second relay; a, i icuit incllidinga back contactbf'said relay, saidfirist contact of said instrlfij exit and agba ckrcontact a' switch 11061; for fireyenfing said switch from 7 being 7move'd fr'om its normal to 'it s reverse 565mm; ,Whe nfsaid switchlocklis ldenergiz ed, a 'first circuit including, a front Contact ofsaidltraek'r'e'lay for nr'gi'zing lsaid, switch lock, and a second'cir'cfiit incliiding'a front amine: of

tact closed; "n the" den'ergzd condition; a track iiistrjrn'i'iitI'G'zite'dfildhgf said "stretch and 'having a coptact fc'l't'jsd'in"fsfionse'to the passage or a train along said stretch; a controlrelay; an energizing'Ycirg'fiiit for said control relayconiprisihgjs'aid cont'acts 'in *seriesja con-V energizing uir'fori 'aidcontrol relay Controlled by said track instr'fiment' andl'sa'idtrack'rel'ay, a stick circuit for said cont'iol"relay 'cohtrolled bysaid track relay, a switch 'lock,a manual contact associated with saidswitch lockfand energizing 'circnit'inans for said switch lockcomprising said manual contact and a contact of said control rlayn V 7J12. 'ln' 'combination with a stretch of track provided with a tracksectionfsaid track section being provided with a track circuit'including a track relay, a track instrumentii'intsaid section, I a'ontrol relay; an energizing circnitfor said'control relayclbsed' whensaid track relay is deenergized and saidatrackiinstrum'ent-isactilatedby thewheels of a train, a stickfcirc'uit for s'aidcontrolrelay closed when said 'cohtrol "relay is energized and saidtrack relay is 'deener'gize'd, a sivitchilock having ,a' manualcontact/and means domprising said maniial Contact, and a cofita'ctof'said control relay for energizing'said switch lock. a

13.. App'a1a'1iisfor controlling Ia railway switchlo'ck connected witha.railwaytswitch associated with a'fsec tiorioof:railwayirack, atrack'relay res ionsive to traflic conditions imsaid' section,;,ac'ontrolrelay, 'a track instrument; located, in saidjsection in approach'to said switch, an energizing circuittfor said control "relaycontrolled byi-Said, track instrument .and said track relay, alstickfcircuit for sa'1d .control relay controlled by said trackrelay;aimanually operable contactfor said switch lock, and aicontrol circuitfor. said switch lock including said; manually operable 'contact'and acontact of said control relay. Y

"izrik ceiciiaf 556160; this patent "UNITED STATES PATENTS 2,448,570Aden 's t. 7, 19:18

